1 /* 2 * Copyright (C) 2007-2012 B.A.T.M.A.N. contributors: 3 * 4 * Marek Lindner, Simon Wunderlich 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of version 2 of the GNU General Public 8 * License as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, but 11 * WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 * General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 18 * 02110-1301, USA 19 * 20 */ 21 22 #include "main.h" 23 #include "hard-interface.h" 24 #include "soft-interface.h" 25 #include "send.h" 26 #include "translation-table.h" 27 #include "routing.h" 28 #include "bat_sysfs.h" 29 #include "originator.h" 30 #include "hash.h" 31 32 #include <linux/if_arp.h> 33 34 35 static int batman_skb_recv(struct sk_buff *skb, 36 struct net_device *dev, 37 struct packet_type *ptype, 38 struct net_device *orig_dev); 39 40 void hardif_free_rcu(struct rcu_head *rcu) 41 { 42 struct hard_iface *hard_iface; 43 44 hard_iface = container_of(rcu, struct hard_iface, rcu); 45 dev_put(hard_iface->net_dev); 46 kfree(hard_iface); 47 } 48 49 struct hard_iface *hardif_get_by_netdev(const struct net_device *net_dev) 50 { 51 struct hard_iface *hard_iface; 52 53 rcu_read_lock(); 54 list_for_each_entry_rcu(hard_iface, &hardif_list, list) { 55 if (hard_iface->net_dev == net_dev && 56 atomic_inc_not_zero(&hard_iface->refcount)) 57 goto out; 58 } 59 60 hard_iface = NULL; 61 62 out: 63 rcu_read_unlock(); 64 return hard_iface; 65 } 66 67 static int is_valid_iface(const struct net_device *net_dev) 68 { 69 if (net_dev->flags & IFF_LOOPBACK) 70 return 0; 71 72 if (net_dev->type != ARPHRD_ETHER) 73 return 0; 74 75 if (net_dev->addr_len != ETH_ALEN) 76 return 0; 77 78 /* no batman over batman */ 79 if (softif_is_valid(net_dev)) 80 return 0; 81 82 /* Device is being bridged */ 83 /* if (net_dev->priv_flags & IFF_BRIDGE_PORT) 84 return 0; */ 85 86 return 1; 87 } 88 89 static struct hard_iface *hardif_get_active(const struct net_device *soft_iface) 90 { 91 struct hard_iface *hard_iface; 92 93 rcu_read_lock(); 94 list_for_each_entry_rcu(hard_iface, &hardif_list, list) { 95 if (hard_iface->soft_iface != soft_iface) 96 continue; 97 98 if (hard_iface->if_status == IF_ACTIVE && 99 atomic_inc_not_zero(&hard_iface->refcount)) 100 goto out; 101 } 102 103 hard_iface = NULL; 104 105 out: 106 rcu_read_unlock(); 107 return hard_iface; 108 } 109 110 static void primary_if_update_addr(struct bat_priv *bat_priv) 111 { 112 struct vis_packet *vis_packet; 113 struct hard_iface *primary_if; 114 115 primary_if = primary_if_get_selected(bat_priv); 116 if (!primary_if) 117 goto out; 118 119 vis_packet = (struct vis_packet *) 120 bat_priv->my_vis_info->skb_packet->data; 121 memcpy(vis_packet->vis_orig, primary_if->net_dev->dev_addr, ETH_ALEN); 122 memcpy(vis_packet->sender_orig, 123 primary_if->net_dev->dev_addr, ETH_ALEN); 124 125 out: 126 if (primary_if) 127 hardif_free_ref(primary_if); 128 } 129 130 static void primary_if_select(struct bat_priv *bat_priv, 131 struct hard_iface *new_hard_iface) 132 { 133 struct hard_iface *curr_hard_iface; 134 135 ASSERT_RTNL(); 136 137 if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount)) 138 new_hard_iface = NULL; 139 140 curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1); 141 rcu_assign_pointer(bat_priv->primary_if, new_hard_iface); 142 143 if (curr_hard_iface) 144 hardif_free_ref(curr_hard_iface); 145 146 if (!new_hard_iface) 147 return; 148 149 bat_priv->bat_algo_ops->bat_ogm_init_primary(new_hard_iface); 150 primary_if_update_addr(bat_priv); 151 } 152 153 static bool hardif_is_iface_up(const struct hard_iface *hard_iface) 154 { 155 if (hard_iface->net_dev->flags & IFF_UP) 156 return true; 157 158 return false; 159 } 160 161 static void check_known_mac_addr(const struct net_device *net_dev) 162 { 163 const struct hard_iface *hard_iface; 164 165 rcu_read_lock(); 166 list_for_each_entry_rcu(hard_iface, &hardif_list, list) { 167 if ((hard_iface->if_status != IF_ACTIVE) && 168 (hard_iface->if_status != IF_TO_BE_ACTIVATED)) 169 continue; 170 171 if (hard_iface->net_dev == net_dev) 172 continue; 173 174 if (!compare_eth(hard_iface->net_dev->dev_addr, 175 net_dev->dev_addr)) 176 continue; 177 178 pr_warning("The newly added mac address (%pM) already exists on: %s\n", 179 net_dev->dev_addr, hard_iface->net_dev->name); 180 pr_warning("It is strongly recommended to keep mac addresses unique to avoid problems!\n"); 181 } 182 rcu_read_unlock(); 183 } 184 185 int hardif_min_mtu(struct net_device *soft_iface) 186 { 187 const struct bat_priv *bat_priv = netdev_priv(soft_iface); 188 const struct hard_iface *hard_iface; 189 /* allow big frames if all devices are capable to do so 190 * (have MTU > 1500 + BAT_HEADER_LEN) */ 191 int min_mtu = ETH_DATA_LEN; 192 193 if (atomic_read(&bat_priv->fragmentation)) 194 goto out; 195 196 rcu_read_lock(); 197 list_for_each_entry_rcu(hard_iface, &hardif_list, list) { 198 if ((hard_iface->if_status != IF_ACTIVE) && 199 (hard_iface->if_status != IF_TO_BE_ACTIVATED)) 200 continue; 201 202 if (hard_iface->soft_iface != soft_iface) 203 continue; 204 205 min_mtu = min_t(int, hard_iface->net_dev->mtu - BAT_HEADER_LEN, 206 min_mtu); 207 } 208 rcu_read_unlock(); 209 out: 210 return min_mtu; 211 } 212 213 /* adjusts the MTU if a new interface with a smaller MTU appeared. */ 214 void update_min_mtu(struct net_device *soft_iface) 215 { 216 int min_mtu; 217 218 min_mtu = hardif_min_mtu(soft_iface); 219 if (soft_iface->mtu != min_mtu) 220 soft_iface->mtu = min_mtu; 221 } 222 223 static void hardif_activate_interface(struct hard_iface *hard_iface) 224 { 225 struct bat_priv *bat_priv; 226 struct hard_iface *primary_if = NULL; 227 228 if (hard_iface->if_status != IF_INACTIVE) 229 goto out; 230 231 bat_priv = netdev_priv(hard_iface->soft_iface); 232 233 bat_priv->bat_algo_ops->bat_ogm_update_mac(hard_iface); 234 hard_iface->if_status = IF_TO_BE_ACTIVATED; 235 236 /** 237 * the first active interface becomes our primary interface or 238 * the next active interface after the old primary interface was removed 239 */ 240 primary_if = primary_if_get_selected(bat_priv); 241 if (!primary_if) 242 primary_if_select(bat_priv, hard_iface); 243 244 bat_info(hard_iface->soft_iface, "Interface activated: %s\n", 245 hard_iface->net_dev->name); 246 247 update_min_mtu(hard_iface->soft_iface); 248 249 out: 250 if (primary_if) 251 hardif_free_ref(primary_if); 252 } 253 254 static void hardif_deactivate_interface(struct hard_iface *hard_iface) 255 { 256 if ((hard_iface->if_status != IF_ACTIVE) && 257 (hard_iface->if_status != IF_TO_BE_ACTIVATED)) 258 return; 259 260 hard_iface->if_status = IF_INACTIVE; 261 262 bat_info(hard_iface->soft_iface, "Interface deactivated: %s\n", 263 hard_iface->net_dev->name); 264 265 update_min_mtu(hard_iface->soft_iface); 266 } 267 268 int hardif_enable_interface(struct hard_iface *hard_iface, 269 const char *iface_name) 270 { 271 struct bat_priv *bat_priv; 272 struct net_device *soft_iface; 273 int ret; 274 275 if (hard_iface->if_status != IF_NOT_IN_USE) 276 goto out; 277 278 if (!atomic_inc_not_zero(&hard_iface->refcount)) 279 goto out; 280 281 /* hard-interface is part of a bridge */ 282 if (hard_iface->net_dev->priv_flags & IFF_BRIDGE_PORT) 283 pr_err("You are about to enable batman-adv on '%s' which already is part of a bridge. Unless you know exactly what you are doing this is probably wrong and won't work the way you think it would.\n", 284 hard_iface->net_dev->name); 285 286 soft_iface = dev_get_by_name(&init_net, iface_name); 287 288 if (!soft_iface) { 289 soft_iface = softif_create(iface_name); 290 291 if (!soft_iface) { 292 ret = -ENOMEM; 293 goto err; 294 } 295 296 /* dev_get_by_name() increases the reference counter for us */ 297 dev_hold(soft_iface); 298 } 299 300 if (!softif_is_valid(soft_iface)) { 301 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n", 302 soft_iface->name); 303 dev_put(soft_iface); 304 ret = -EINVAL; 305 goto err; 306 } 307 308 hard_iface->soft_iface = soft_iface; 309 bat_priv = netdev_priv(hard_iface->soft_iface); 310 311 bat_priv->bat_algo_ops->bat_ogm_init(hard_iface); 312 313 if (!hard_iface->packet_buff) { 314 bat_err(hard_iface->soft_iface, 315 "Can't add interface packet (%s): out of memory\n", 316 hard_iface->net_dev->name); 317 ret = -ENOMEM; 318 goto err; 319 } 320 321 hard_iface->if_num = bat_priv->num_ifaces; 322 bat_priv->num_ifaces++; 323 hard_iface->if_status = IF_INACTIVE; 324 orig_hash_add_if(hard_iface, bat_priv->num_ifaces); 325 326 hard_iface->batman_adv_ptype.type = __constant_htons(ETH_P_BATMAN); 327 hard_iface->batman_adv_ptype.func = batman_skb_recv; 328 hard_iface->batman_adv_ptype.dev = hard_iface->net_dev; 329 dev_add_pack(&hard_iface->batman_adv_ptype); 330 331 atomic_set(&hard_iface->seqno, 1); 332 atomic_set(&hard_iface->frag_seqno, 1); 333 bat_info(hard_iface->soft_iface, "Adding interface: %s\n", 334 hard_iface->net_dev->name); 335 336 if (atomic_read(&bat_priv->fragmentation) && hard_iface->net_dev->mtu < 337 ETH_DATA_LEN + BAT_HEADER_LEN) 338 bat_info(hard_iface->soft_iface, 339 "The MTU of interface %s is too small (%i) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to %zi would solve the problem.\n", 340 hard_iface->net_dev->name, hard_iface->net_dev->mtu, 341 ETH_DATA_LEN + BAT_HEADER_LEN); 342 343 if (!atomic_read(&bat_priv->fragmentation) && hard_iface->net_dev->mtu < 344 ETH_DATA_LEN + BAT_HEADER_LEN) 345 bat_info(hard_iface->soft_iface, 346 "The MTU of interface %s is too small (%i) to handle the transport of batman-adv packets. If you experience problems getting traffic through try increasing the MTU to %zi.\n", 347 hard_iface->net_dev->name, hard_iface->net_dev->mtu, 348 ETH_DATA_LEN + BAT_HEADER_LEN); 349 350 if (hardif_is_iface_up(hard_iface)) 351 hardif_activate_interface(hard_iface); 352 else 353 bat_err(hard_iface->soft_iface, 354 "Not using interface %s (retrying later): interface not active\n", 355 hard_iface->net_dev->name); 356 357 /* begin scheduling originator messages on that interface */ 358 schedule_bat_ogm(hard_iface); 359 360 out: 361 return 0; 362 363 err: 364 hardif_free_ref(hard_iface); 365 return ret; 366 } 367 368 void hardif_disable_interface(struct hard_iface *hard_iface) 369 { 370 struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface); 371 struct hard_iface *primary_if = NULL; 372 373 if (hard_iface->if_status == IF_ACTIVE) 374 hardif_deactivate_interface(hard_iface); 375 376 if (hard_iface->if_status != IF_INACTIVE) 377 goto out; 378 379 bat_info(hard_iface->soft_iface, "Removing interface: %s\n", 380 hard_iface->net_dev->name); 381 dev_remove_pack(&hard_iface->batman_adv_ptype); 382 383 bat_priv->num_ifaces--; 384 orig_hash_del_if(hard_iface, bat_priv->num_ifaces); 385 386 primary_if = primary_if_get_selected(bat_priv); 387 if (hard_iface == primary_if) { 388 struct hard_iface *new_if; 389 390 new_if = hardif_get_active(hard_iface->soft_iface); 391 primary_if_select(bat_priv, new_if); 392 393 if (new_if) 394 hardif_free_ref(new_if); 395 } 396 397 kfree(hard_iface->packet_buff); 398 hard_iface->packet_buff = NULL; 399 hard_iface->if_status = IF_NOT_IN_USE; 400 401 /* delete all references to this hard_iface */ 402 purge_orig_ref(bat_priv); 403 purge_outstanding_packets(bat_priv, hard_iface); 404 dev_put(hard_iface->soft_iface); 405 406 /* nobody uses this interface anymore */ 407 if (!bat_priv->num_ifaces) 408 softif_destroy(hard_iface->soft_iface); 409 410 hard_iface->soft_iface = NULL; 411 hardif_free_ref(hard_iface); 412 413 out: 414 if (primary_if) 415 hardif_free_ref(primary_if); 416 } 417 418 static struct hard_iface *hardif_add_interface(struct net_device *net_dev) 419 { 420 struct hard_iface *hard_iface; 421 int ret; 422 423 ASSERT_RTNL(); 424 425 ret = is_valid_iface(net_dev); 426 if (ret != 1) 427 goto out; 428 429 dev_hold(net_dev); 430 431 hard_iface = kmalloc(sizeof(*hard_iface), GFP_ATOMIC); 432 if (!hard_iface) 433 goto release_dev; 434 435 ret = sysfs_add_hardif(&hard_iface->hardif_obj, net_dev); 436 if (ret) 437 goto free_if; 438 439 hard_iface->if_num = -1; 440 hard_iface->net_dev = net_dev; 441 hard_iface->soft_iface = NULL; 442 hard_iface->if_status = IF_NOT_IN_USE; 443 INIT_LIST_HEAD(&hard_iface->list); 444 /* extra reference for return */ 445 atomic_set(&hard_iface->refcount, 2); 446 447 check_known_mac_addr(hard_iface->net_dev); 448 list_add_tail_rcu(&hard_iface->list, &hardif_list); 449 450 return hard_iface; 451 452 free_if: 453 kfree(hard_iface); 454 release_dev: 455 dev_put(net_dev); 456 out: 457 return NULL; 458 } 459 460 static void hardif_remove_interface(struct hard_iface *hard_iface) 461 { 462 ASSERT_RTNL(); 463 464 /* first deactivate interface */ 465 if (hard_iface->if_status != IF_NOT_IN_USE) 466 hardif_disable_interface(hard_iface); 467 468 if (hard_iface->if_status != IF_NOT_IN_USE) 469 return; 470 471 hard_iface->if_status = IF_TO_BE_REMOVED; 472 sysfs_del_hardif(&hard_iface->hardif_obj); 473 hardif_free_ref(hard_iface); 474 } 475 476 void hardif_remove_interfaces(void) 477 { 478 struct hard_iface *hard_iface, *hard_iface_tmp; 479 480 rtnl_lock(); 481 list_for_each_entry_safe(hard_iface, hard_iface_tmp, 482 &hardif_list, list) { 483 list_del_rcu(&hard_iface->list); 484 hardif_remove_interface(hard_iface); 485 } 486 rtnl_unlock(); 487 } 488 489 static int hard_if_event(struct notifier_block *this, 490 unsigned long event, void *ptr) 491 { 492 struct net_device *net_dev = ptr; 493 struct hard_iface *hard_iface = hardif_get_by_netdev(net_dev); 494 struct hard_iface *primary_if = NULL; 495 struct bat_priv *bat_priv; 496 497 if (!hard_iface && event == NETDEV_REGISTER) 498 hard_iface = hardif_add_interface(net_dev); 499 500 if (!hard_iface) 501 goto out; 502 503 switch (event) { 504 case NETDEV_UP: 505 hardif_activate_interface(hard_iface); 506 break; 507 case NETDEV_GOING_DOWN: 508 case NETDEV_DOWN: 509 hardif_deactivate_interface(hard_iface); 510 break; 511 case NETDEV_UNREGISTER: 512 list_del_rcu(&hard_iface->list); 513 514 hardif_remove_interface(hard_iface); 515 break; 516 case NETDEV_CHANGEMTU: 517 if (hard_iface->soft_iface) 518 update_min_mtu(hard_iface->soft_iface); 519 break; 520 case NETDEV_CHANGEADDR: 521 if (hard_iface->if_status == IF_NOT_IN_USE) 522 goto hardif_put; 523 524 check_known_mac_addr(hard_iface->net_dev); 525 526 bat_priv = netdev_priv(hard_iface->soft_iface); 527 bat_priv->bat_algo_ops->bat_ogm_update_mac(hard_iface); 528 529 primary_if = primary_if_get_selected(bat_priv); 530 if (!primary_if) 531 goto hardif_put; 532 533 if (hard_iface == primary_if) 534 primary_if_update_addr(bat_priv); 535 break; 536 default: 537 break; 538 } 539 540 hardif_put: 541 hardif_free_ref(hard_iface); 542 out: 543 if (primary_if) 544 hardif_free_ref(primary_if); 545 return NOTIFY_DONE; 546 } 547 548 /* incoming packets with the batman ethertype received on any active hard 549 * interface */ 550 static int batman_skb_recv(struct sk_buff *skb, struct net_device *dev, 551 struct packet_type *ptype, 552 struct net_device *orig_dev) 553 { 554 struct bat_priv *bat_priv; 555 struct batman_ogm_packet *batman_ogm_packet; 556 struct hard_iface *hard_iface; 557 int ret; 558 559 hard_iface = container_of(ptype, struct hard_iface, batman_adv_ptype); 560 skb = skb_share_check(skb, GFP_ATOMIC); 561 562 /* skb was released by skb_share_check() */ 563 if (!skb) 564 goto err_out; 565 566 /* packet should hold at least type and version */ 567 if (unlikely(!pskb_may_pull(skb, 2))) 568 goto err_free; 569 570 /* expect a valid ethernet header here. */ 571 if (unlikely(skb->mac_len != sizeof(struct ethhdr) || 572 !skb_mac_header(skb))) 573 goto err_free; 574 575 if (!hard_iface->soft_iface) 576 goto err_free; 577 578 bat_priv = netdev_priv(hard_iface->soft_iface); 579 580 if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE) 581 goto err_free; 582 583 /* discard frames on not active interfaces */ 584 if (hard_iface->if_status != IF_ACTIVE) 585 goto err_free; 586 587 batman_ogm_packet = (struct batman_ogm_packet *)skb->data; 588 589 if (batman_ogm_packet->header.version != COMPAT_VERSION) { 590 bat_dbg(DBG_BATMAN, bat_priv, 591 "Drop packet: incompatible batman version (%i)\n", 592 batman_ogm_packet->header.version); 593 goto err_free; 594 } 595 596 /* all receive handlers return whether they received or reused 597 * the supplied skb. if not, we have to free the skb. */ 598 599 switch (batman_ogm_packet->header.packet_type) { 600 /* batman originator packet */ 601 case BAT_OGM: 602 ret = recv_bat_ogm_packet(skb, hard_iface); 603 break; 604 605 /* batman icmp packet */ 606 case BAT_ICMP: 607 ret = recv_icmp_packet(skb, hard_iface); 608 break; 609 610 /* unicast packet */ 611 case BAT_UNICAST: 612 ret = recv_unicast_packet(skb, hard_iface); 613 break; 614 615 /* fragmented unicast packet */ 616 case BAT_UNICAST_FRAG: 617 ret = recv_ucast_frag_packet(skb, hard_iface); 618 break; 619 620 /* broadcast packet */ 621 case BAT_BCAST: 622 ret = recv_bcast_packet(skb, hard_iface); 623 break; 624 625 /* vis packet */ 626 case BAT_VIS: 627 ret = recv_vis_packet(skb, hard_iface); 628 break; 629 /* Translation table query (request or response) */ 630 case BAT_TT_QUERY: 631 ret = recv_tt_query(skb, hard_iface); 632 break; 633 /* Roaming advertisement */ 634 case BAT_ROAM_ADV: 635 ret = recv_roam_adv(skb, hard_iface); 636 break; 637 default: 638 ret = NET_RX_DROP; 639 } 640 641 if (ret == NET_RX_DROP) 642 kfree_skb(skb); 643 644 /* return NET_RX_SUCCESS in any case as we 645 * most probably dropped the packet for 646 * routing-logical reasons. */ 647 648 return NET_RX_SUCCESS; 649 650 err_free: 651 kfree_skb(skb); 652 err_out: 653 return NET_RX_DROP; 654 } 655 656 /* This function returns true if the interface represented by ifindex is a 657 * 802.11 wireless device */ 658 bool is_wifi_iface(int ifindex) 659 { 660 struct net_device *net_device = NULL; 661 bool ret = false; 662 663 if (ifindex == NULL_IFINDEX) 664 goto out; 665 666 net_device = dev_get_by_index(&init_net, ifindex); 667 if (!net_device) 668 goto out; 669 670 #ifdef CONFIG_WIRELESS_EXT 671 /* pre-cfg80211 drivers have to implement WEXT, so it is possible to 672 * check for wireless_handlers != NULL */ 673 if (net_device->wireless_handlers) 674 ret = true; 675 else 676 #endif 677 /* cfg80211 drivers have to set ieee80211_ptr */ 678 if (net_device->ieee80211_ptr) 679 ret = true; 680 out: 681 if (net_device) 682 dev_put(net_device); 683 return ret; 684 } 685 686 struct notifier_block hard_if_notifier = { 687 .notifier_call = hard_if_event, 688 }; 689